Video compression systems that implement standards such as MPEG2 or MPEG4/H264 are usually designed to reduce the bit rate of the input video to levels that permit affordable transmission of high quality pictures. It is usual that several video services are multiplexed into a fixed bit rate Transport Stream [TS] that will occupy convenient channels of known transmission systems. Various complex control mechanisms exist for controlling the bit rate of the video services, based in part of their content, and are typically used for direct broadcasting of video services to the home. In some situations, video services are combined and transmitted for the purposes of returning original material to a central studio or processing centre, for example for Digital Satellite News Gathering [DSNG] or so-called “Contribution” or “Back Haul”. In these situations the usual complex method of controlling the total bit rate for home distribution is not appropriate. Typically the number of channels is limited, for example 4 or 5, and the bit rates for each video service are set manually by an experienced on-site operator.